中文摘要：

研究TN型液晶光栅的光程差与衍射特性的关系．用扭曲角及延迟量测试仪CG-200测量施加电压区光程差随电压的变化，根据光程差计算透过率，再与由显示器测量系统DMS-301测得的加电压区透过率比较．实验结果表明，无电压区光程差不变，有电压区光程差逐渐减小，光强重新分布．当电压从1．0V升到1．6V时，光程差减小缓慢，有微弱的衍射现象；当电压升高到2．0V时，光程差急剧下降，出现明显的衍射现象．实现了液晶光栅的电控衍射光强分布．

英文摘要：

In this paper, a type of connection existing between the light path difference and electro-optic diffraction characteristic of twisted nematie liquid crystal grating is studied. The light path difference is measured by CG-200 in apply voltage region. The light path difference was measured by DMS-301. When voltage increased from 1.0 V to 1.6 V, the light path difference reduced slowly from 433 nm to 424.2 nm, and faint diffraction phenomenon is produced; when voltage increased from 1.6 V to 2.0 V, it reduced rapidly from 424.2 nm to 358.2 nm, and diffraction phenomenon is produced. The light path difference of no applied voltage regions is unchanged, while it is becoming smaller. The light intensity is redistricted, and the diffraction of liquid crystal grating is controlled by voltage.